1. Field of Invention
The present invention is related to a pump.
2. Related Prior Art
Various pumps have been devised to pump air into various articles such as tires and balls. For example, Taiwanese Patent Publication No. 200910 teaches a conventional pump as shown in Fig. 6. This conventional pump includes a cylinder, a plunger for cooperating with the cylinder to produce compressed air, a reservoir for storing the compressed air and a pedal for stablizing the pump in operation. The reservoir is installed on one side of the cylinder, and the pedal is mounted on an opposite side of the cylinder. In operation, a user sets one foot on the pedal, and operates the plunger with his or her hands. Since only one side of the pump is subject to a portion of the user""s weight, the pump tends to swing in operation, thus reducing the efficiency of pumping.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is an objective of the present invention to provide a pump.
In the present invention, a pump includes a cylinder, a plunger for compressing air in the cylinder, a reservoir formed around the cylinder so as to define a space for storing a portion of the compressed air, a valve device installed in the cylinder for transfer of the compressed air from the cylinder into the reservoir and a base connected with the cylinder for stabilizing the pump. The base includes two pedals extending in opposite directions from the cylinder.
The cylinder includes an upper chamber in which the plunger is inserted, a lower chamber in which the valve device is installed and a hole communicating the upper chamber with the lower chamber, and the lower chamber is in communication with the space.
The cylinder includes two annular portions formed on opposite sides of the lower chamber for sealing the space. Two rings are mounted on the annular portions of the cylinder for sealing the space.
The valve device includes a shell, a check valve and two rings. The shell includes a chamber defined therein, an inlet in communication with the chamber and an outlet in communication with the chamber. The check valve is installed in the chamber for transfer of the compressed air from the inlet to the outlet. The rings are mounted on the shell on two opposite sides of the inlet for defining an annular space as communication between the hole and the inlet.
The reservoir includes a channel in communication with the space. The channel includes an enlarged terminal portion for receiving a pressure meter.